EnviroKerb® & ETI – permeable kerb inlets

In the system

Where the units sit in the TNS™

Downstream of the units, which are the entry point, the water ramp, drainage cell, tank module, structural soil cells and tree pit make up the retention and storage asset.

Labelled cutaway of the TNS – pavement, EnviroKerb, water ramp unit, Rainsmart Nero Pave cell, tank module, Terravault structural soil cells and tree pit

Labelled cutaway: rain enters at the kerb line, passes the water ramp unit into the drainage cell and tank module, then down through the structural soil cells to the tree root zone. A small relief pipe at the base engages only once the connected systems have filled and the substrate is fully saturated.

A hand lifting the galvanised tray out of the ETI body using the cast-in Gatic locator

Serviceability

The tray lifts straight out

With the access locator cast into the galvanised steel tray, cleaning and replacement is a lift-out operation, not a break-out.

Top view of the ETI tray set flush into the precast kerb body

In the kerb line

Flush, trafficable, unremarkable

Sitting flush in the channel with a Class D load rating, the tray behaves like the kerb and channel either side of it.

The units

One unit is a tray, the other is the kerb itself

Both replace conventional kerb and channel, and both are interchangeable via cast-in threaded lifting sleeves – so a unit can be lifted out and swapped without breaking out the kerb line.

ETI unit on a pallet – precast concrete kerb body with a galvanised steel tray filled with permeable concrete, set on a precast water ramp

Upstream · everyday rain

ETI – EnviroKerb Tray Inlet

The ETI is a precast kerb and channel unit with a built-in galvanised steel tray filled with permeable concrete. It sits within the kerb on a precast concrete water ramp that directs surface water towards the back of the kerb.

Takes water in at the kerb line on the everyday rainfall that makes up most of the annual volume.
A load-bearing permeable aggregate enclosed in an engineered frame, Class D rated and fully trafficable.
Coarse and fine surface material is retained in the tray and kept from travelling downstream (PPC Australia).
The tray lifts out via a standard Gatic locator cast into it – cleaned or replaced in minutes.

Close-up of the fully porous EnviroKerb permeable concrete kerb with cast-in threaded lifting sleeves

Downstream · heavy rain

EnviroKerb® High Flow Inlet

A fully porous precast kerb made from PPC Australia's patented permeable concrete formula. It sits immediately downgradient of the ETI, over its own precast water ramp that deflects water away from the pavement subgrade.

Accepts water across the whole kerb face rather than at a single point.
Precast kerb body 1000 × 600 mm, matching the ETI.
Interchangeable via cast-in threaded lifting sleeves
Serviced with conventional street sweeper and vacuum truck methods – nothing proprietary to maintain.

How they work together. The ETI sits upstream, where the everyday rain runs, with fully porous EnviroKerb® units downstream, adjacent to it, taking water across the whole kerb face. In the TNS™, an ARI Water Filter beneath the ETI tray protects the void structure from fines and is replaced by removal.

Durability at the kerb edge

Both kerb units are precast and manufactured by PPC Australia, then delivered to site finished and ready to set in the channel. The permeable concrete in the ETI sits inside a galvanised steel tray whose frame protects the edges of the permeable concrete from wheels and sweepers. The EnviroKerb® unit is one permeable concrete mix through its full depth, with no surface coat or topping that can separate from the body.

Units at the Bondi site, constructed in 2022, have kept their top edge and channel face intact, with the aggregate still fully bound in. Spalling, in the materials FAQ →

ETI · technical data

Specifications, weights and dimensions

Manufacturer data, PPC Australia – brochures PPCA-BRO-001 and PPCA-BRO-002, Rev B, September 2026. Confirm current figures against the current brochure obtained from PPC Australia before specifying.

Precast concrete kerb body

ETI and EnviroKerb unit

Length: 1000 mm
Width: 600 mm
Channel thickness: 200 mm
Throat opening: 700 × 235 mm (ETI only)
Weight: ~200 kg

Tray insert

Galvanised steel, permeable concrete fill

Tray: 800 × 350 × 45 mm
Lifting locator: Standard Gatic
Load rating: Class D
Weight: ~19 kg

Precast concrete water ramp

Deflects water away from the subgrade

Length: 995 mm
Width: 595 mm
Height: 200 mm
Lifting threads: Cast-in M16
Weight: ~200 kg

Water passing through the permeable kerb face during a test

How the water gets in, and where it goes

Water passes through the permeable concrete at the kerb line in place of running along the channel to a pit. The precast water ramp beneath deflects it away from the road pavement subgrade and towards the nature strip, into the adjacent soil profile or the storage built behind the kerb.

TNS™ hydrologic and hydraulic performance is designed and assessed against Australian Rainfall and Runoff (ARR), the national standard applying in every state. The local drainage manual applies where an authority adds its own requirements.

On capacity. BGI does not publish an inlet capacity or a permeability rate for the kerb units. The number of units at a node is a design output, calculated from the micro-catchment runoff for the site in question. Material performance figures are a matter for the manufacturer's own published literature.

Attribution and scope. EnviroKerb® and the ETI are products of PPC Australia Pty Ltd, and their product literature and product data are theirs. Specify from the current brochure obtained from PPC Australia, which BGI does not host or republish. BGI specifies these units as the entry point to the TNS™ and makes no stormwater quality claim for the TNS™. Where a project carries stormwater quality obligations, those are met by separate, appropriately certified measures.

Materials. The elements water touches – the ETI tray cover, the EnviroKerb body and the water ramp – are mineral aggregate and cement as standard. The materials case →

The EnviroKerb range

Any kerb profile, plus made-to-measure

EnviroKerb can be installed as a standalone item in any profile to replace traditional concrete kerb and channel. It can also be used with structural soil cells to form the below-ground retention the TNS™ is built on.

Profiles

Each unit is manufactured to match the kerb profile the road already uses, which keeps the streetscape reading as normal kerb and channel.

Barrier kerb and channel
Spoon drain
Roll-over kerb and channel
Flat slab
Made to measure

Maintenance

Cleaning uses conventional street sweeper and vacuum truck methods, programmed into a council's existing maintenance rounds. On the TNS™, Matter SensAI sensors measure intake against a calibrated baseline and flag an inspection when intake drops, before a blockage forms.

Applications

Wherever runoff currently leaves a hard surface faster than the vegetation beside it can use.

Roads, car parks, hardstand
Street tree and nature strip
Public open space
Retrofit of existing kerb

Retrofit

Because units are interchangeable via cast-in lifting sleeves, an existing kerb run can be opened, a unit dropped in, and the run closed again, with no redesign of the surface network.

“EnviroKerb technology aims to reverse the way water is handled in our streets – capturing it at the source and returning it to the trees, gardens and green spaces that make our cities liveable.”

Martin Cook · Director, PPC Australia

Once it is a council asset

Serviced with the equipment councils already own

The program follows the condition of the asset, not a testing regime. Crews work with standard sweeping and pressure equipment, with no specialist skills, instruments or confined space entry. Cleaning keeps water passing through the asset and is not carried out as stormwater treatment.

The tray takes the first flush

At the upstream end of the run, the ETI meets the first flush of each event and the material carried with it. It is also the one component that lifts out on a Gatic locator, flushes clean and goes back in minutes. By design, the most serviceable part of the run carries its heaviest load. Keeping the tray clear is what protects the rest of the units along the run.

Cleaned on rounds you already run

Mechanical cleaning is programmed into the same street rounds as the surrounding kerb. Only vacuum or regenerative air sweepers are used, because a rotary broom pushes fines down into the voids and clogs the unit. Organic material breaks down and washes through on its own; soil, sand and construction fines are what actually matter.

Evidence, not the calendar

Where Matter SensAI intake monitoring is installed at the connected node, it learns the normal intake pattern and notifies the maintenance team when intake drops at a specific unit. Attendance is triggered by the asset itself, with no schedule or manual checking needed.

If in doubt, tip a bucket of water in.

A crew needs only that test, which has three outcomes: water that disappears means the asset is working; water that drains slowly means the next clean comes forward; and water that runs along the channel means booking the vacuum truck.

Maintenance Schedule (PPCA-OM-001). PPC Australia's full schedule for asset owners and maintenance contractors – equipment and protection, escalation steps, replacement, and the controls that keep soil and construction fines off the asset during nearby works. The schedule is currently in review and is available on request from BGI.

Specify the units

Tell us the catchment and we’ll tell you the count

The number of ETI and EnviroKerb units is calculated from the micro-catchment runoff for each node. Send us the site and the catchment plan to have the units sized for every node.

Book a technical chat

Water in at the kerb line – two units, one job